1091820001 has 2 divisors, whose sum is σ = 1091820002. Its totient is φ = 1091820000.

The previous prime is 1091819983. The next prime is 1091820073. The reversal of 1091820001 is 1000281901.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1085768401 + 6051600 = 32951^2 + 2460^2 .

It is a cyclic number.

It is not a de Polignac number, because 1091820001 - 2¹⁷ = 1091688929 is a prime.

It is not a weakly prime, because it can be changed into another prime (1091820091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 545910000 + 545910001.

It is an arithmetic number, because the mean of its divisors is an integer number (545910001).

Almost surely, 2^1091820001 is an apocalyptic number.

It is an amenable number.

1091820001 is a deficient number, since it is larger than the sum of its proper divisors (1).

1091820001 is an equidigital number, since it uses as much as digits as its factorization.

1091820001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 22.

The square root of 1091820001 is about 33042.6996627092. The cubic root of 1091820001 is about 1029.7149432677.

The spelling of 1091820001 in words is "one billion, ninety-one million, eight hundred twenty thousand, one".